

function isBlank(){
	var msg='';
	if(trim(document.timesheet.start_date_for_month.value).length==0){
		msg=msg + 'From date should not be blank.\n'; 
	}
	if(trim(document.timesheet.end_date_for_month.value).length==0){
		msg=msg + 'To date should not be blank.\n'; 
	}
	if(!chkDates()){
		msg=msg + 'From date should be less than or equal to To date.\n'; 
	}

	if(msg.length>0){
		alert(msg);
	}else{
		document.forms.timesheet.submit();
	}
}
function chkDates(){
	if(document.timesheet.start_date_for_month.value.length==0 || document.timesheet.end_date_for_month.value.length==0)
		return true;
	return (isFirstBeforeSecond(document.timesheet.start_date_for_month.value,document.timesheet.end_date_for_month.value));
}